“Sustainability” has many definitions. A commonly cited definition is one put forward by the Brundtland Commission in a report of the World Commission on Environment and Development entitled "Our Common Future" (December 11, 1987). The Commission defined sustainable development as development that “meets the needs of the present without compromising the ability of future generations to meet their own needs.” Not focused solely on environmental sustainability, the Commission’s report emphasized the inter-related nature of environmental, economic, and social factors in sustainability. One of the keys to success in sustainability is recognizing that decision making must be based on an integration of economic with environmental and social factors.
Three important guiding principles central to a successful approach are:
• Flexible — In an environment where what we understand and can predict is still developing and will be uncertain for some time to come, providing ways to monitor, assess, adapt, and to be flexible in our responses will be critical. Climate change is but one example; the uncertainties acknowledged in that subject area should be instructive in helping us understand that a flexible approach is necessary when addressing all areas of sustainability.
• Holistic — The components of sustainability – in terms of both its inputs and outputs –are complex and synergistic. No single action will result in a sustainable result, and sustainable initiatives taken in one area don’t necessarily lead to sustainability in another. For example, sustainable land use practices don’t necessarily result in a sustainable transportation or health system. A holistic approach is required that includes all levels of governance and encompasses planning, funding, evaluation, monitoring, and implementation.
• Long-term — Focusing on short-term, expedient solutions will only make actions necessary to support sustainability more difficult to take in the future. For example, in the areas of environmental issues and climate change, deferred action now will only make the cumulative effects more difficult to resolve in the future. The familiar GMA-based 20-year planning timeframe will not be sufficient – planning for sustainability must take an even longer view.